Conventional MRI techniques use linear B0 gradients for spatial encoding. However, B0 gradients have high cost and bulk, and lead to patient discomfort via acoustic noise and peripheral nerve stimulation. A few spatial encoding methods have been proposed that use only RF gradient coils, which would not suffer the drawbacks of B0 gradients. However, existing RF gradient encoding methods severely restrict the types of sequences and subsequently image contrast that can be obtained. What is needed is an RF encoding method that leads to the same orthogonality between spatial encoding and image contrast that is enjoyed by conventional B0 gradients.